Dr. Thomas Cornwell with a patient, Mary Hanrahan, at her home. “For the horribly sick, hospitals are the worst place,” he says.CreditWhitten Sabbatini for The New York Times

REMEMBER when doctors made house calls?

While only a relative handful of doctors still offer them, there is growing evidence that comprehensive home medical care could be a viable alternative to the attendant woes and soaring expenses of institutional health services, particularly for those in late retirement.

It will take some important legislative changes before focused, less intrusive care in a dignified, comfortable setting can become more widely available. The polarizing politics surrounding the Affordable Care Act makes any reform to the health care system particularly challenging. Still, given the overall popularity of Medicare — Hillary Clinton and Donald Trump both say they support it — getting a new home medical care benefit through Congress looks more promising.

At the heart of the home care renaissance is a combination of high-tech, portable medical equipment and the age-old practice of doctors coming into the home to personally examine and treat their patients.

“We can do X-rays, EKGs, medical records and other applications in the home,” said Dr. Thomas Cornwell, who has made more than 32,000 house calls in his Chicago-based practice and wants to see Medicare support more home-based medical care.

“I had a 92-year-old patient with a very high temperature,” Dr. Cornwell said, citing an example. “I brought in a portable X-ray and diagnosed pneumonia; she didn’t have to go to the hospital, and lived four more years.”

Dr. Cornwell is spearheading a national effort to revive physician house calls even as he pushes for doctors to be more fully compensated by Medicare for doing them. He is also training doctors to offer home-based care through the House Call Project, which is sponsored by the Home Centered Care Institute. He is chief executive of the nonprofit institute.

Home medical care may well be the key missing link in the “aging in place” model aimed at helping millions more older adults avoid spending the last years of their lives in nursing homes and other institutions.

Over the past decades, however, home care has been dwarfed by the significant shift of treatment to offices, clinics and hospitals. More than 50,000 practitioners work exclusively in hospitals, compared to about 5,000 doctors who make home-based visits to Medicare patients.

But a modest counterrevolution toward home care, devoted to a lower-cost, patient-centered approach, is underway. House calls to Medicare patients rose from 1.5 million in 1995 to more than 2.6 million in 2014, according to the Centers for Medicare and Medicaid Services.

Dr. Cornwell used his smartphone to read Ms. Hanrahan’s heart rate.CreditWhitten Sabbatini for The New York Times

Generally, the most expensive patients to treat have myriad health problems like diabetes and congestive heart failure. The top 5 percent of care-intensive patients account for 50 percent of total medical expenses, according to government data, with a median cost of more than $43,000 per person.

Dr. Cornwell and others argue that many of these gravely ill Americans can be better cared for — at less overall expense — at home.

“People want to be at home,” said Dr. Joanne G. Schwartzberg, a scholar-in-residence at the Accreditation Council for the Graduate Medical Education, who is working with Dr. Cornwell to advance home-based care. “Research has shown that these patients have better health outcomes at much lower costs. Now the challenge is to train more physicians in providing this complex but rewarding form of medical care.”

There are signs that the triad of care using doctors, nurses and the latest technology could help patients with multiple conditions.

Linda V. DeCherrie, who runs one of the largest academic house call programs in the country out of the Icahn School of Medicine at Mount Sinai Hospital in Manhattan, received a $9.6 million Medicare innovation award to study the expansion of home care “to include hospital level care at home and what it means for patients.”

Dr. DeCherrie, who supervises two programs at Mount Sinai that treat more than 1,500 patients, says comprehensive home-based health care “has the potential to provide solutions for many problems,” suggesting that seeing patients in their natural environment may offer improved care.

“It can be quite an ordeal to see a doctor in a hospital if you are a frail older adult,” Dr. DeCherrie said. “Patients are much happier not to have to go through that. In a home, you can get a better picture of what’s going on.”

The next step for broad-based home medical care is a legislative push to expand Medicare’s reach into the home and to revamp the prevailing fee-for-service model that rewards quantity of treatment over quality and cost savings.

A medical assistant, Rachel Kay, takes notes during a house call. Electronic medical records and portable diagnostic equipment like X-ray and EKG machines make home care easier.CreditWhitten Sabbatini for The New York Times

Unless the traditional economic model is changed, experts say, few doctors would be interested in providing home-based care. It’s often a money loser for physicians under the current system.

Dr. Cornwell said he would like to see a new payment model that would allow Medicare to share any savings — relative to hospitalization — with doctors who make house calls.

“It would have profound national impact,” Dr. Cornwell said. “It would save billions in health care costs. For the horribly sick, hospitals are the worst place.”

The Independence at Home Act (S. 3130), a bill supported by a bipartisan group of senators, would expand a Medicare home care demonstration program “so that it can benefit more Medicare beneficiaries with severe chronic illness and disability through coordinated, home-based primary care,” according to an endorsement letter backed by organizations including AARP and the Retirement Research Foundation.

The first phase of the home medical care program demonstrated medical cost savings of $35 million — ranging from $1,000 to $3,000 per patient. Another independent study conducted by the Department of Veterans Affairs showed a 24 percent reduction in total costs and 62 percent fewer hospital stays, translating to some $9,000 in savings per veteran using home-based care.

Although the home medical care bill is unlikely to see action in Congress this year, Dr. Cornwell hopes it may be revived next year. But many policy, fiscal and political hurdles need to be crossed before home care can really take off.

How will doctors be monitored in the home? How will Medicare gauge the effectiveness of home-based treatments? Will Medicare reimbursement be enough to cover the costs of physicians, nurses and equipment? What about long-term care financing in addition to primary care that could provide better funding for custodial care outside of nursing homes?

Those questions, among others, are being considered by a diverse group of lawmakers, health care professionals and Medicare officials. Whether long-term care costs, which often include nonmedical caregiver or semiskilled home care, should also receive more support through government programs is another challenging issue.

“Many people who need help with basic tasks of daily life want to and can remain at home, rather than being forced to live in institutions in order to get care,” said Judith Feder, a professor of public policy at Georgetown.

The image of a doctor making house calls may recall a quaint Norman Rockwellesque painting, but home medical care could be part of a better future, too.